1. Field of the Invention
The present invention relates generally to a method and apparatus for managing digital image data. More particularly, the present invention is an apparatus and method for increasing the image capture rate of a digital camera by delaying image processing and compression.
2. Description of the Background Art
Still-cameras are often required to capture images at rates which vary depending on their selected photographic targets. For example, during a fast-moving sporting event, still-cameras may be required to capture a series of images during a relatively short time period. Thus, an important still-camera performance feature is the capture rate for successive sets of image data.
Another important still-camera performance feature is the number of captured images that can be stored in the camera's finite memory. To maximize the image-carrying capacity of digital still-cameras, it is desirable to compress the images prior to storage. Conventional digital cameras typically perform image processing on the raw image data and then use a high-quality image compression routine (such as JPEG) to compress the image data.
Photographers, however, may want to capture another image before the camera has completed the time-consuming image processing and compression of raw image data. Therefore, the above processing and compression technique can effectively lower the successive image capture rate.
One common approach for minimizing the image processing and compression time is through the use of custom-designed Application Specific Integrated Circuits (ASICs). Typically, up to three relatively expensive ASICs may be required to perform the image processing and compression operations. While such ASIC-based cameras perform the required image processing and compression operations very quickly, their increased cost may render such cameras less attractive to the mainstream consumer market.
To make the digital cameras more affordable, manufacturers have replaced many of the costly ASICs with functionally equivalent software-based routines. The software-based routines may be stored within standard ROM chips and they can also be readily updated by rewriting a portion of the software. Software-based cameras, however, typically require an inordinately long time to perform the image processing and compression operations. This results in slower successive image capture rates and limits the marketability of the software-based digital still-cameras.
Therefore, what is needed is an apparatus and method that enables a relatively low-cost, software-based digital camera to attain higher successive image capture rates.